Explanation: NGC 6888,
also known as the Crescent Nebula, is a
cosmic bubble
about 25 light-years across, blown by
winds
from its central, bright, massive star.
Near the center of this intriguing widefield
view of interstellar gas clouds and
rich star fields of the
constellation Cygnus, NGC 6888 is about 5,000 light-years away.
The three color composite image was created
by stacking exposures through narrow band filters that
transmit the light
from atoms in the clouds.
Hydrogen is shown as green, sulfur as red, and oxygen as blue.
NGC 6888's central star is classified as a
Wolf-Rayet
star (WR 136) and is shedding its outer envelope in a strong
stellar wind, ejecting the equivalent of our Sun's mass
every 10,000 years.
Burning fuel at a prodigious rate and near the end of its
stellar life,
this star should ultimately go out with a bang in a spectacular
supernova explosion.